1. Field of the Invention
The invention relates to a steering system.
2. Description of the Related Art
A structure for preventing half-lock, for example, in a steering system in which tilt adjustment can be made has been proposed. With this structure, in the course of engaging first lock teeth with second lock teeth, a guide projection that projects from a tooth tip of at least one of the first lock teeth is engaged with the corresponding second lock teeth before the remaining first lock teeth are engaged with the corresponding second lock teeth, so that the first lock teeth and the second lock teeth are aligned with each other as a whole. In this way, occurrence of half-lock is restricted. See Japanese Patent Application Publication No. 2010-264870 (JP 2010-264870 A), for example.
Japanese Patent Application Publication No. 2008-81026 (JP 2008-81026 A) describes a lock structure using engagement of teeth, in which the height of a specific tooth out of the teeth is made higher than that of the remaining teeth and the pressure angle of the specific tooth is made smaller than that of the remaining teeth.
In the structure described in JP 2010-264870 A, the guide projection that projects from the tooth tip has an insufficient strength and is not formed with ease. This exerts disadvantageous effect on the manufacturing. In the structure described in JP 2008-81026 A, the pressure angle of at least one of the teeth is made different from that of the remaining teeth. This makes the manufacturing difficult.